Replace GetDelegate() return of PLMO* with const PLMO&.

The PageLoadMetricsObserverDelegate returns global state about page
loads that PageLoadMetricsObservers should have access to. Interfacing
with it only requires a const& since every API call is const.

BUG=993367

Change-Id: I7aa66649862e7d42cf55fcce4fe9e3d14d0e80c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1756165Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Commit-Queue: Justin Miron <justinmiron@google.com>
Cr-Commit-Position: refs/heads/master@{#687639}

chrome/browser/page_load_metrics/observers/ad_metrics/ads_page_load_metrics_observer.cc

@@ -170,7 +170,7 @@ void AdsPageLoadMetricsObserver::MaybeTriggerHeavyAdIntervention(
   // Ensure that this RenderFrameHost is a subframe.
   DCHECK(render_frame_host->GetParent());
 
-  GetDelegate()->GetWebContents()->GetController().LoadErrorPage(
+  GetDelegate().GetWebContents()->GetController().LoadErrorPage(
       render_frame_host, render_frame_host->GetLastCommittedURL(),
       heavy_ads::PrepareHeavyAdPage(), net::ERR_BLOCKED_BY_CLIENT);
 
@@ -188,7 +188,7 @@ void AdsPageLoadMetricsObserver::OnCpuTimingUpdate(
   DCHECK(!timing.task_time.is_zero());
 
   // If the page is backgrounded, don't update CPU times.
-  if (!GetDelegate()->GetVisibilityTracker().currently_in_foreground())
+  if (!GetDelegate().GetVisibilityTracker().currently_in_foreground())
     return;
 
   // Get the current time, considered to be when this update occurred.
@@ -313,7 +313,7 @@ void AdsPageLoadMetricsObserver::FrameReceivedFirstUserActivation(
       FindFrameData(render_frame_host->GetFrameTreeNodeId());
   if (ancestor_data) {
     ancestor_data->SetReceivedUserActivation(
-        GetDelegate()->GetVisibilityTracker().GetForegroundDuration());
+        GetDelegate().GetVisibilityTracker().GetForegroundDuration());
   }
 }
 
@@ -326,7 +326,7 @@ AdsPageLoadMetricsObserver::FlushMetricsOnAppEnterBackground(
   if (extra_info.did_commit) {
     if (timing.response_start) {
       time_commit_ =
-          GetDelegate()->GetNavigationStart() + *timing.response_start;
+          GetDelegate().GetNavigationStart() + *timing.response_start;
     }
     RecordHistograms(extra_info.source_id);
   }
@@ -338,7 +338,7 @@ void AdsPageLoadMetricsObserver::OnComplete(
     const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
   if (info.did_commit && timing.response_start)
-    time_commit_ = GetDelegate()->GetNavigationStart() + *timing.response_start;
+    time_commit_ = GetDelegate().GetNavigationStart() + *timing.response_start;
   RecordHistograms(info.source_id);
 }
 
@@ -356,10 +356,10 @@ void AdsPageLoadMetricsObserver::OnPageInteractive(
     const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
   if (timing.interactive_timing->interactive) {
-    time_interactive_ = GetDelegate()->GetNavigationStart() +
+    time_interactive_ = GetDelegate().GetNavigationStart() +
                         *timing.interactive_timing->interactive;
     pre_interactive_duration_ =
-        GetDelegate()->GetVisibilityTracker().GetForegroundDuration();
+        GetDelegate().GetVisibilityTracker().GetForegroundDuration();
     page_ad_bytes_at_interactive_ = aggregate_frame_data_->ad_network_bytes();
   }
 }
@@ -397,7 +397,7 @@ void AdsPageLoadMetricsObserver::MediaStartedPlaying(
     const content::WebContentsObserver::MediaPlayerInfo& video_type,
     content::RenderFrameHost* render_frame_host) {
   aggregate_frame_data_->set_media_status(FrameData::MediaStatus::kPlayed);
-  if (render_frame_host == GetDelegate()->GetWebContents()->GetMainFrame())
+  if (render_frame_host == GetDelegate().GetWebContents()->GetMainFrame())
     main_frame_data_->set_media_status(FrameData::MediaStatus::kPlayed);
 
   FrameData* ancestor_data =
@@ -429,7 +429,7 @@ void AdsPageLoadMetricsObserver::OnFrameDeleted(
                            render_frame_host->GetFrameTreeNodeId()) {
     RecordPerFrameHistogramsForAdTagging(*ancestor_data);
     RecordPerFrameHistogramsForCpuUsage(*ancestor_data);
-    ancestor_data->RecordAdFrameLoadUkmEvent(GetDelegate()->GetSourceId());
+    ancestor_data->RecordAdFrameLoadUkmEvent(GetDelegate().GetSourceId());
     DCHECK(id_and_data->second != ad_frames_data_storage_.end());
     ad_frames_data_storage_.erase(id_and_data->second);
   }
@@ -458,7 +458,7 @@ int AdsPageLoadMetricsObserver::GetUnaccountedAdBytes(
   content::GlobalRequestID global_request_id(process_id, resource->request_id);
 
   // Resource just started loading.
-  if (!GetDelegate()->GetResourceTracker().HasPreviousUpdateForResource(
+  if (!GetDelegate().GetResourceTracker().HasPreviousUpdateForResource(
           global_request_id))
     return 0;
 
@@ -466,7 +466,7 @@ int AdsPageLoadMetricsObserver::GetUnaccountedAdBytes(
   // but was not before, we need to account for all the previously received
   // bytes.
   auto const& previous_update =
-      GetDelegate()->GetResourceTracker().GetPreviousUpdateForResource(
+      GetDelegate().GetResourceTracker().GetPreviousUpdateForResource(
           global_request_id);
   bool is_new_ad = !previous_update->reported_as_ad_resource;
   return is_new_ad ? resource->received_data_length - resource->delta_bytes : 0;
@@ -478,12 +478,12 @@ void AdsPageLoadMetricsObserver::ProcessResourceForPage(
   auto mime_type = FrameData::GetResourceMimeType(resource);
   int unaccounted_ad_bytes = GetUnaccountedAdBytes(process_id, resource);
   aggregate_frame_data_->ProcessResourceLoadInFrame(
-      resource, process_id, GetDelegate()->GetResourceTracker());
+      resource, process_id, GetDelegate().GetResourceTracker());
   if (unaccounted_ad_bytes)
     aggregate_frame_data_->AdjustAdBytes(unaccounted_ad_bytes, mime_type);
   if (resource->is_main_frame_resource) {
     main_frame_data_->ProcessResourceLoadInFrame(
-        resource, process_id, GetDelegate()->GetResourceTracker());
+        resource, process_id, GetDelegate().GetResourceTracker());
     if (unaccounted_ad_bytes)
       main_frame_data_->AdjustAdBytes(unaccounted_ad_bytes, mime_type);
   }
@@ -534,7 +534,7 @@ void AdsPageLoadMetricsObserver::ProcessResourceForFrame(
     ancestor_data->AdjustAdBytes(unaccounted_ad_bytes, mime_type);
   ancestor_data->ProcessResourceLoadInFrame(
       resource, render_frame_host->GetProcess()->GetID(),
-      GetDelegate()->GetResourceTracker());
+      GetDelegate().GetResourceTracker());
   MaybeTriggerHeavyAdIntervention(render_frame_host, ancestor_data);
 }
 
@@ -612,7 +612,7 @@ void AdsPageLoadMetricsObserver::RecordPerFrameHistogramsForCpuUsage(
     const FrameData& ad_frame_data) {
   // Get the relevant durations, set pre-interactive if the page never hit it.
   base::TimeDelta total_duration =
-      GetDelegate()->GetVisibilityTracker().GetForegroundDuration();
+      GetDelegate().GetVisibilityTracker().GetForegroundDuration();
   if (time_interactive_.is_null())
     pre_interactive_duration_ = total_duration;
   base::TimeDelta post_interactive_duration =
@@ -649,7 +649,7 @@ void AdsPageLoadMetricsObserver::RecordPerFrameHistogramsForCpuUsage(
         ADS_HISTOGRAM("Cpu.AdFrames.PerFrame.PeakWindowStartTime",
                       PAGE_LOAD_HISTOGRAM, visibility,
                       ad_frame_data.peak_window_start_time().value() -
-                          GetDelegate()->GetNavigationStart());
+                          GetDelegate().GetNavigationStart());
       }
     }
 
@@ -713,7 +713,7 @@ void AdsPageLoadMetricsObserver::RecordAggregateHistogramsForCpuUsage() {
 
   // Get the relevant durations, set pre-interactive if the page never hit it.
   base::TimeDelta total_duration =
-      GetDelegate()->GetVisibilityTracker().GetForegroundDuration();
+      GetDelegate().GetVisibilityTracker().GetForegroundDuration();
   if (time_interactive_.is_null())
     pre_interactive_duration_ = total_duration;
 
@@ -746,7 +746,7 @@ void AdsPageLoadMetricsObserver::RecordAggregateHistogramsForCpuUsage() {
       ADS_HISTOGRAM("Cpu.FullPage.PeakWindowStartTime", PAGE_LOAD_HISTOGRAM,
                     visibility,
                     aggregate_frame_data_->peak_window_start_time().value() -
-                        GetDelegate()->GetNavigationStart());
+                        GetDelegate().GetNavigationStart());
     }
   }
   if (pre_interactive_duration_.InMilliseconds() > 0) {

chrome/browser/page_load_metrics/observers/android_page_load_metrics_observer.cc

@@ -109,7 +109,7 @@ void AndroidPageLoadMetricsObserver::OnLoadedResource(
 void AndroidPageLoadMetricsObserver::ReportNewNavigation() {
   DCHECK_GE(navigation_id_, 0);
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onNewNavigation(env, java_web_contents,
                                        static_cast<jlong>(navigation_id_));
@@ -120,7 +120,7 @@ void AndroidPageLoadMetricsObserver::ReportNetworkQualityEstimate(
     int64_t http_rtt_ms,
     int64_t transport_rtt_ms) {
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onNetworkQualityEstimate(
       env, java_web_contents, static_cast<jlong>(navigation_id_),
@@ -132,7 +132,7 @@ void AndroidPageLoadMetricsObserver::ReportFirstContentfulPaint(
     int64_t navigation_start_tick,
     int64_t first_contentful_paint_ms) {
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onFirstContentfulPaint(
       env, java_web_contents, static_cast<jlong>(navigation_id_),
@@ -144,7 +144,7 @@ void AndroidPageLoadMetricsObserver::ReportFirstMeaningfulPaint(
     int64_t navigation_start_tick,
     int64_t first_meaningful_paint_ms) {
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onFirstMeaningfulPaint(
       env, java_web_contents, static_cast<jlong>(navigation_id_),
@@ -156,7 +156,7 @@ void AndroidPageLoadMetricsObserver::ReportLoadEventStart(
     int64_t navigation_start_tick,
     int64_t load_event_start_ms) {
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onLoadEventStart(
       env, java_web_contents, static_cast<jlong>(navigation_id_),
@@ -173,7 +173,7 @@ void AndroidPageLoadMetricsObserver::ReportLoadedMainResource(
     int64_t send_start_ms,
     int64_t send_end_ms) {
   base::android::ScopedJavaLocalRef<jobject> java_web_contents =
-      GetDelegate()->GetWebContents()->GetJavaWebContents();
+      GetDelegate().GetWebContents()->GetJavaWebContents();
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_PageLoadMetrics_onLoadedMainResource(
       env, java_web_contents, static_cast<jlong>(navigation_id_),

chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc

@@ -933,7 +933,7 @@ void CorePageLoadMetricsObserver::RecordByteAndResourceHistograms(
 
   size_t unfinished_bytes = 0;
   for (auto const& kv :
-       GetDelegate()->GetResourceTracker().unfinished_resources())
+       GetDelegate().GetResourceTracker().unfinished_resources())
     unfinished_bytes += kv.second->received_data_length;
   PAGE_BYTES_HISTOGRAM(internal::kHistogramPageLoadUnfinishedBytes,
                        unfinished_bytes);

chrome/browser/page_load_metrics/observers/data_reduction_proxy_metrics_observer_base.cc

@@ -311,9 +311,9 @@ void DataReductionProxyMetricsObserverBase::SendPingback(
           timing.parse_timing->parse_stop, info)) {
     parse_stop = timing.parse_timing->parse_stop;
   }
-  if (GetDelegate()->DidCommit() && main_frame_fetch_start_) {
+  if (GetDelegate().DidCommit() && main_frame_fetch_start_) {
     main_frame_fetch_start =
-        main_frame_fetch_start_.value() - GetDelegate()->GetNavigationStart();
+        main_frame_fetch_start_.value() - GetDelegate().GetNavigationStart();
   }
   if (info.started_in_foreground && info.page_end_time.has_value()) {
     // This should be reported even when the app goes into the background which

chrome/browser/page_load_metrics/observers/data_use_metrics_observer.cc

@@ -44,12 +44,12 @@ void DataUseMetricsObserver::OnResourceDataUseObserved(
     received_data_length += resource->delta_bytes;
     chrome_data_use_measurement->RecordContentTypeMetric(
         resource->mime_type, resource->is_main_frame_resource,
-        GetDelegate()->GetVisibilityTracker().currently_in_foreground(),
+        GetDelegate().GetVisibilityTracker().currently_in_foreground(),
         resource->delta_bytes);
   }
   if (!received_data_length)
     return;
   chrome_data_use_measurement->ReportUserTrafficDataUse(
-      GetDelegate()->GetVisibilityTracker().currently_in_foreground(),
+      GetDelegate().GetVisibilityTracker().currently_in_foreground(),
       received_data_length);
 }

chrome/browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer.cc

@@ -28,7 +28,7 @@ void HttpsEngagementPageLoadMetricsObserver::OnComplete(
 
   // Don't record anything if the user never saw it.
   base::TimeDelta foreground_time =
-      GetDelegate()->GetVisibilityTracker().GetForegroundDuration();
+      GetDelegate().GetVisibilityTracker().GetForegroundDuration();
   if (foreground_time.is_zero())
     return;
 

chrome/browser/page_load_metrics/observers/loading_predictor_page_load_metrics_observer.cc

@@ -74,7 +74,7 @@ LoadingPredictorPageLoadMetricsObserver::OnHidden(
 void LoadingPredictorPageLoadMetricsObserver::OnFirstContentfulPaintInPage(
     const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& extra_info) {
-  predictors::NavigationID navigation_id(GetDelegate()->GetWebContents());
+  predictors::NavigationID navigation_id(GetDelegate().GetWebContents());
 
   collector_->RecordFirstContentfulPaint(
       navigation_id, extra_info.navigation_start +

chrome/browser/page_load_metrics/observers/resource_metrics_observer.cc

@@ -50,7 +50,7 @@ void ResourceMetricsObserver::OnComplete(
     const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
   for (auto const& kv :
-       GetDelegate()->GetResourceTracker().unfinished_resources())
+       GetDelegate().GetResourceTracker().unfinished_resources())
     RecordResourceHistograms(kv.second);
 }
 

chrome/browser/page_load_metrics/observers/security_state_page_load_metrics_observer.cc

@@ -162,7 +162,7 @@ void SecurityStatePageLoadMetricsObserver::OnComplete(
   base::UmaHistogramCustomTimes(
       security_state::GetSecurityLevelHistogramName(kTimeOnPagePrefix,
                                                     current_security_level_),
-      GetDelegate()->GetVisibilityTracker().GetForegroundDuration(),
+      GetDelegate().GetVisibilityTracker().GetForegroundDuration(),
       base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromHours(1), 100);
   base::UmaHistogramEnumeration(kSecurityLevelOnComplete,
                                 current_security_level_,

chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.cc

@@ -532,19 +532,19 @@ void UkmPageLoadMetricsObserver::ReportMainResourceTimingMetrics(
       request_start_to_receive_headers_end_ms);
 
   if (!main_frame_timing_->request_start.is_null() &&
-      !GetDelegate()->GetNavigationStart().is_null()) {
+      !GetDelegate().GetNavigationStart().is_null()) {
     base::TimeDelta navigation_start_to_request_start =
-        main_frame_timing_->request_start - GetDelegate()->GetNavigationStart();
+        main_frame_timing_->request_start - GetDelegate().GetNavigationStart();
 
     builder->SetMainFrameResource_NavigationStartToRequestStart(
         navigation_start_to_request_start.InMilliseconds());
   }
 
   if (!main_frame_timing_->receive_headers_start.is_null() &&
-      !GetDelegate()->GetNavigationStart().is_null()) {
+      !GetDelegate().GetNavigationStart().is_null()) {
     base::TimeDelta navigation_start_to_receive_headers_start =
         main_frame_timing_->receive_headers_start -
-        GetDelegate()->GetNavigationStart();
+        GetDelegate().GetNavigationStart();
     builder->SetMainFrameResource_NavigationStartToReceiveHeadersStart(
         navigation_start_to_receive_headers_start.InMilliseconds());
   }
@@ -659,7 +659,7 @@ void UkmPageLoadMetricsObserver::OnTimingUpdate(
 void UkmPageLoadMetricsObserver::OnCpuTimingUpdate(
     content::RenderFrameHost* subframe_rfh,
     const page_load_metrics::mojom::CpuTiming& timing) {
-  if (GetDelegate()->GetVisibilityTracker().currently_in_foreground())
+  if (GetDelegate().GetVisibilityTracker().currently_in_foreground())
     total_foreground_cpu_time_ += timing.task_time;
 }
 

chrome/browser/page_load_metrics/page_load_metrics_observer.cc

@@ -190,8 +190,9 @@ bool PageLoadMetricsObserver::AssignTimeAndSizeForLargestContentfulPaint(
   return true;
 }
 
-PageLoadMetricsObserverDelegate* PageLoadMetricsObserver::GetDelegate() const {
-  return delegate_;
+const PageLoadMetricsObserverDelegate& PageLoadMetricsObserver::GetDelegate()
+    const {
+  return *delegate_;
 }
 
 void PageLoadMetricsObserver::SetDelegate(

chrome/browser/page_load_metrics/page_load_metrics_observer.h

@@ -293,7 +293,7 @@ class PageLoadMetricsObserver {
   // Gets/Sets the delegate. The delegate must outlive the observer and is
   // normally set when the observer is first registered for the page load. The
   // delegate can only be set once.
-  PageLoadMetricsObserverDelegate* GetDelegate() const;
+  const PageLoadMetricsObserverDelegate& GetDelegate() const;
   void SetDelegate(PageLoadMetricsObserverDelegate*);
 
   // The page load started, with the given navigation handle.